What you do is put in a band you like, and it will automatically play similar bands. It also has a "like" or "dislike" function. So if a song comes up you dont like, you hit dislike, and it wont play it again. The more you do this, the more it narrow downs your taste.
Keep in mind though, the more you hit like or dislike, the more it will start repeating all the same bands. So especially if your looking for new bands, dont even use that function, and it will just keep playing through the genre. Every time something comes up you like, write it down! I have found countless of new bands doing this.
If your looking for a whole new genre all together, you can also choose to listen to a genre rather than putting in a specific band.